Types A, Y, YF Parallel Shaft DrivesTypes AB & YB Horizontal Right Angle Drives

FALK™ MAGNUM SEAL™ SYSTEM SELECTION GUIDE

The Falk Magnum Seal™ Keeps oil in

Keeps dirt out

A new standard for performance For years, the standard for shaft sealing in the parallel shaft andhorizontal right angle reducers was the single or double-lippedcontact seal. They worked relatively well if they were handledgently and installed properly, if the shaft was plunge-ground andnot scratched and if they were protected from abrasive material.Since they are “contact,” eventually this contact wears materialaway and leakage occurs. It will happen sooner or later.

Falk™ has now changed that with a good idea, the Magnum™seal system. It’s simple-the oil seal has no wearing parts. Thatmeans no leaks. It will last as long as the reducer.

A short history of shaft seals The Challenge

Since standard enclosed speed reducers were first produced byFalk™, we’ve searched for the answer to a problem. If precisiongears are to perform satisfactorily, lubricant must be retained inthe gearbox and external contaminants must be kept out.However, the input and output shafts extend through the housingwalls and provide a path from the inside to outside of theenclosure and vice versa. And, of course, both of these shaftsrotate. So the challenge is simply this, what is the most effectiveand economical device to keep oil in and keep dirt out?

Sleeve Bearings

When sleeve bearings were commonly used, this rotary shaft sealtook the form of a labyrinth sealing arrangement, requiring closefitting mating surfaces, including straight, tapered, andinterlocking shapes. In the early days, Falk™ even used a devicewith a mercury barrier to prevent oil leakage. These methodsworked well if the close tolerances were maintained. They werevery expensive and difficult to manufacture.

Anti-friction Bearings

With the development of anti-friction bearings as a veryeconomical alternative to sleeve bearings, the sealing methodchanged. Larger radial clearances were required for anti-frictionbearings, and contact seals in various flexible materials becameavailable. Contact (lip-type) seals were promoted as a non-leaking seal. However, an oil film is required between the seal lip and theshaft to prevent wear on the seal lip. If wear results, then leakswould occur. With close shaft tolerances, plunge-ground surfacefinishes and careful handling and assembly, contact seals wereadequate for most applications.

In 1978, seal manufacturers stated that even with excellentmanufacturing and application conditions, contact lip seals wouldeventually wear and leak.

The Answer

At this time Falk™ intensified its search for a standard shaft sealthat would not leak. This development and testing involved manydifferent concepts, from multiple labyrinth designs with slingers, tobaffles, bushings and wiper combinations. The seal developmentspecifications were exacting:

1) It must be incorporated as a standard design. 2) It must satisfy the customer. It must work.

After four years of tests, Falk™ engineers came up with a goodidea-the Magnum Seal System™.

Any good idea is basically simple, and the way the Magnum™seal works is simple.

It Keeps Oil In

The location of the inner seal cage to the bearing race and to theshaft form a throttling bush seal. Oil is retained in the housing byvery close fitting tolerances in both the radial and axial directions.These tight clearances make it difficult for oil to get out, but stillpermit shaft rotation, since there is no contact. But what insures an effective oil seal, is a drain back feature. Under normal operatingconditions, no oil comes through the bush seal. However, if oildoes get through, it immediately returns to the unit through drainback passages in the inner seal cage and the housing wall. Sincethere are no wearing parts, the Magnum seal lasts the life of thegear reducer.

It Keeps Dirt Out

The second feature of the Magnum™ seal is the ability to keepcontaminants out. An outer cover assembly, when filled withgrease, traps abrasive particles. A single lip-type seal is effective in preventing the grease and contaminants from entering the innerseal area. Periodically, introducing fresh grease through thegrease fitting in the cover will purge contaminants.

Leaks Cost Money

When seals leak, the reducer loses lubricant vital to the life of thegear elements and bearings. As a result, gears and bearings canfail long before their time. That’s expensive. And leaks are messy,the unit and floor get covered with oil. It’s a real housekeepingproblem. Also, airborne contaminants stick to the oil, which isunsightly.

Repair Downtime

In some cases, a lip seal can be easily replaced, however, whenconnected equipment must be moved or the drive is part of acontinuous process, the job takes longer and costs more.

In theory, lip-type seals run on a film of oil between the seal lip andthe shaft. Airborne particles, which are present in most industrialareas, embed themselves in the seal lips. As a result, a groove isworn in the shaft and oil leaks through. Replacing the seal won’thelp. The leak will still be there because of the grooved shaft.Reconditioning or replacing the shaft can be very costly and requiremore downtime than production will allow–not a good solution. The simple, less costly solution is the Falk Magnum Seal™.

2 (141-110.2) © Rexnord Industries, LLC, 1983,1987.

OIL SUMP

GREASE

DRAIN BACKPASSAGE

OIL

BEARING ROLLERS

RADIAL BUSH

AXIAL BUSHEXCLUSIONLIP SEAL

SHAFT CENTERLINE

Copyright 1983, 1987, Rexnord Industries, LLC. Rexnord,Steelflex, and “A GoodName in Industry,” are registered trademarks of Rexnord Industries, LLC. Falk is atrademark of Rexnord. The MAGNUM SEAL is a trademark of Falk for its rotary shaftsealing system for enclosed gear drives. All rights reserved. September 1987.

Reduced Maintenance, Reduced Downtime

You’ll never have to worry about dirt or grit getting into thebearings of any properly maintained Falk™ speed reducer. Norwill you ever have to wipe up an oil leak. Falk’s exclusive Magnum Seal™ (below) assures it. With this design, a unique drain backpassage works in conjunction with both radial and axial bush seals to effectively retain lubricant in the inner chamber. On a very fewhigh-oil requirements, two tandem lip-type seals may be usedinstead of the bush seal design.

Then, at the outboard side of the seal, a purgeable greasechamber provides an effective barrier to the infiltration of dirt orgrime. The end result: Dirt stays out. Oil stays in.

To further maximize gear, bearing, and lubricant life, every Falk™speed reducer is designed for an oil sump temperature of no more than 200°F. This provides a “thermal margin” that some of today’s manufacturers simply do not offer. It’s one more reason Falk™speed reducers stay on the job, even in the toughest applications.

Matched To Your Needs

No speed reducer, regardless of how well designed and built, willperform efficiently if it’s mismatched to the application. So it’sworth knowing that when you come to Rexnord, you deal withNorth America’s most experienced producer of gear drives...offering today’s widest selection of standard reducers to fit virtually any application.

Service That Never Stops

Wherever you are, Falk™ parts and service are nearby, with 4distribution centers and more than 600 distributors located acrossNorth America. This network provides day and night service plusspare parts availability. It’s our way of saying that we understandthe vital importance of keeping your plant equipment running...and do something about it. No customer has ever been withoutproduct or service because of a Rexnord work stoppage.

Confidence

Rexnord has been serving the needs of heavy industry for nearly100 years. Over this span of time, widespread acceptance of ourproducts has made us the nation’s largest and most diversifiedsource of gear drives and related equipment. We take thisleadership role seriously, and stand solidly behind what we buildand what we sell. It is this sincere concern for our customers’welfare that has led to Falk’s™ reputation as “A Good Name inIndustry.”™

© Rexnord Industries, LLC, 1983, 1987. (141-110.2) 3

Magnum Seal For Types A, AB, Y, YB, and YF Speed Reducers

GREASE FITTING

GREASE

GREASEEXCLUSIONSEAL

DRAIN BACK PASSAGE

OIL TO BEARING

RADIAL BUSH SEAL

AXIAL BUSH SEAL

BEARING

OIL

INSIDEREDUCER

Standard Availability

Type Y and YF speed reducers are furnished with the fullMagnum™ seal system as is Type YB low speed shafts. Due tospace limitations, the housing drain back holes are not furnishedon Type YB high speed shafts. Type YB high speed shafts arefurnished with one or two, single lip seals with a grease purgecover or cage.

The thoroughly tested Magnum seal design effectively seals oil inand prevents the entry of dust and water. The Magnum™ seal issuitable for operation in atmospheres laden with contaminantsand abrasive dusts such as taconite.

The grease purge cover or cage prevents the ingress of foreignmatter. Contaminated grease can be purged from the assembly by introducing fresh grease through the grease fitting. Contaminatedgrease will be forced out along the shaft.

The usable shaft extensions with Magnum™ seal are slightlyreduced compared to reducers with a single, dual-lip seal. Thesevalues are listed below.

Retrofitting

The Magnum™ seal system can be installed on Type Y, YF, and YB reducers that were originally equipped with standard single,dual-lip seals or optional grease purged assembly. Manual148-140 provides instructions for ordering and installation. Boththe inner seal cage and the grease-purge cover/cage are required for field retrofitting and some external piping or housing drilling isrequired.

4 (141-110.2) © Rexnord Industries, LLC, 1983,1987.

Type Y, YB, and YF Speed Reducers

GREASE-PURGEC0VER

EXCLUSIONLIP SEAL

DRAIN BACKPASSAGE

HOUSING WALL

INNER SEAL CAGEGREASE FITTING

GREASE-PURGECAGE

EXCLUSIONLIP SEALDRAIN BACK

PASSAGE

DRAIN BACKPASSAGE

HOUSINGWALL

INNER SEAL CAGE

GREASE FITTING

SIZES 2050-2135

SIZES 1080-1195& 2140-2195

For the sizes shown above,the grease-purge coverconsists of a one-piecestamped cup design with agrease fitting for purging the contaminants. The exclusionlip seal is seated in the inner seal cage.

For the sizes shown above,the grease purge cage is asplit assembly. Theexclusion lip seal andgrease fitting are located in the grease purge cage.

GREASE FITTING

GREASE PURGE CAGE

EXCLUSION LIP SEAL

INNER SEAL CAGE

TABLE 2 — Type YF

DRIVESIZE LSS

High Speed Shaft

Dia Length Dia Length

1080 6 3/8 2 1/2 4 1/8 3 1/4 51/41090 7 1/4 2 3/4 4 5/8 3 1/4 51/41100 8 1/4 3 5 1/8 3 1/2 5 5/8 1110 9 1/16 3 1/4 5 5/16 4 5 11/16

1120/25 9 7/8 3 1/2 5 13/16 4 6 5/16 1130/35 10 11/ I6 4 1/2 7 7/16 . . . . . .1140/45 12 1/8 5 8 1/4 5 1/2 9 1/8 1150/55 12 5/8 5 8 5/16 6 9 11/16 1160/65 13 13/16 5 1/2 9 5/16 6 1/2 10 1/8 1110/15 15 1/16 5 1/2 9 3/8 7 11 3/4 1180/85 16 11/16 6 93/4 7 1/4 12 1/2 1190/95 18 11/16 6 1/2 10 3/8 7 3/4 12 1/2

Q Dimensions shown are for shaft diameters 3.00, 3.25, & 3.50 respectively. Largediameter usable lengths are as follows: 2170/75=81/8, 2180/85=9, 2190/95 =95/8.

Usable Shaft Lengths for Units with Magnum Seal™ System

TABLE 1 — Types Y and YB

DRIVESIZE

LSSY & YB

High Speed Shaft

Y1 Y2 Y3 YB2 YB3 YB4

2050 4 3 1/16 2 1/4 2 1/16 2 3/8 2 1/16 2 1/16 2060 4 13/16 3 3/8 2 5/8 2 1/16 3 2 1/16 2 1/16 2010 5 3/8 3 7/8 3 1/16 2 7/16 3 7/16 2 5/8 2 1/16 2080 6 7/16 4 1/8 3 3/8 2 7/16 3 13/16 2 5/8 2 1/16 2090 7 1/16 4 3/4 3 7/8 2 7/8 3 7/16 3 2 1/16 2100 8 1/4 5 9/16 4 1/8 2 7/8 4 5/8 3 1 13/16 2110 9 1/16 5 11/16 4 3/4 3 3/16 4 5/8 3 7/16 1 13/16

2120/25 9 7/8 6 5/16 5 9/16 3 1/2 5 3/16 3 7/16 2 5/8 2130/35 10 11/16 6 3/4 6 3 1/2 5 9/16 3 13 /16 2 5/8 2140/45 12 1/8 8 5/8 5 15/16 4 1/16 5 3/4 3 7/16 . . . 2150/55 12 5/8 . . . 5 15/16 4 5/16 6 9/16 4 5/8 . . . 2160/65 13 13/16 . . . 6 13/16 5 1/16 7 1/2 4 5/8 . . . 2110/15 15 1/16 . . . 7 9/16 5 13/16 8 1/8 5 3/16 Q . . . 2180/85 16 11/16 . . . 8 7/16 5 7/8 9 5 9/16 Q . . .2190/95 18 11/16 . . . 9 3/8 6 7/16 9 5/8 5 3 /4 Q . . .